Aetiology

The incidence of chemical injuries to the eye has been reported to be 10.7 per 100,000 population per annum, representing an estimated 10% of ocular trauma treated in emergency departments. Most patients are males of working age (M:F ratio = 3-8:1). The age-specific risk is highest in children aged 1-4 years, often due to exposure to household cleaning and disinfection products

A wide variety of chemicals can be responsible for ocular injury, including:

Alkalis, such as:

• ammonia compounds (household cleaners, fertiliser)
• sodium hydroxide (drain and oven cleaners)
• lime, i.e. calcium hydroxide (cement, plaster)

(NB alkalis can cause more severe injuries through liquefactive necrosis which aids deeper penetration of the chemical agent)

Acids, such as:

• sulphuric (car batteries)
• hydrofluoric (glass etching)
• hydrochloric (>25% is corrosive)
• glacial acetic (wart, verruca treatment)
• citric (limescale removal)

(NB acids typically cause coagulative necrosis which limits penetration into the eye)

Detergents, such as:

• chemicals found in washing powders and laundry pods, capsules or tablets

Disinfection agents, such as:

• free chlorine liberating compounds including sodium hypochlorite (bleach)

Solvents, such as:

• paint thinners
• petrol
• nail varnish remover

Fixatives, such as:

• formaldehyde
• glutaraldehyde

Contact lens solutions including hydrogen peroxide; 

In clinical practice, tonometer disinfection fluids
Pepper spray, tear gases (CS, CN, CR)
Cyano-acrylate adhesive (superglue) – tube can be confused with eye drops or ointment
Artificial eyelash glue 
Eyelash tinting solutions 
Alcohol-based hand sanitiser

Predisposing factors

Domestic accidents, DIY injuries
Industrial injuries
Assault
Riot control
Warfare

Symptoms of chemical trauma

Immediate pain, redness, epiphora
Visual loss
Severe chemical trauma may be relatively pain free (damage to superficial nerves)

Signs of chemical trauma

Burns to eyelids and surrounding skin
Particulate matter under lid (evert to examine)
Conjunctival chemosis, hyperaemia and epithelial damage
Limbal and conjunctival blanching (cessation of blood flow in superficial vessels; indicates poor prognosis). Risk of limbal stem cell damage

Corneal epithelial defects ranging from superficial punctate keratitis through focal epithelial loss to sloughing of the entire epithelium
Corneal oedema and haze 
Corneal opacification in severe cases (may prevent view of anterior chamber, iris, lens or beyond)
Raised IOP

Various chemical trauma classification systems exist, e.g. those of Roper-Hall and Dua and the International Life Sciences Institute’s (ILSI) classification. Each of these establishes limbal ischaemia as dividing mild from more severe trauma

Differential diagnosis

Corneal abrasion
Other causes of acute red eye; history should aid the diagnosis

Management by optometrist

Practitioners should recognise their limitations and where necessary seek further advice or refer the patient elsewhere

Immediate management

• the amount of time that elapses between the initial exposure and irrigation significantly impacts the prognosis. Therefore, it is critical to perform large-volume irrigation as soon as possible
• irrigation should begin immediately at the scene of the accident with any non-toxic liquid (e.g. tap water)
• on presentation to clinical care and before examination, the patient should receive copious prolonged irrigation of the eyes with sterile normal saline (at least one litre); if not immediately available, use tap water
• irrigate for 15-30 min (with intermittent topical anaesthetic if required) or until pH between 7 and 8 (normal value 7.4, range 7.3 – 7.7): to measure, cease irrigation, wait for 1 min, apply universal indicator paper to fornix
• when pH normal, check again after additional 30 min
• lower lid eversion and upper lid eversion (double eversion if possible) to check for presence of particulate matter
• remove any particulate matter, sweeping the fornices with a moistened cotton bud
• ascertain which chemical caused the injury
• check VA (important even if pain and/or swollen lids make this difficult)
• advise no contact lens wear until after satisfactory review

(GRADE*: Level of evidence=moderate, Strength of recommendation=strong)

In severe cases (i.e. where there is limbal ischaemia or loss of corneal transparency), no pharmacological intervention (immediate referral)
In mild cases, give ocular lubricants (preferably unpreserved) for symptomatic relief and to aid re-epithelialisation; consider topical antibiotics for prophylaxis if there is a significant corneal epithelial defect

Consider cycloplegia to alleviate pupil spasm (e.g. unpreserved  gutt cyclopentolate 1% twice daily) 
(GRADE*: Level of evidence=low, Strength of recommendation=weak)

For pain or photophobia, advise systemic analgesia and darkened room/sunglasses
(GRADE*: Level of evidence=low, Strength of recommendation=strong)

Management category

In severe cases:
A2: first aid measures and immediate referral to A&E. 
Emphasise to the patient the urgency of the condition and instruct them to attend the local hospital eye department or hospital A&E the same day, explaining that you will leave a message so that they are expected. Telephone the department to explain what you have done, preferably leaving your message with a doctor or other health care professional.
In mild cases:
B2: alleviation/palliation (normally no referral)

Possible management by ophthalmologist

Further irrigation
Admission to hospital where necessary
Treatment with topical antibiotics, topical steroid, topical and/or systemic ascorbic acid, topical sodium citrate, oral tetracycline, systemic acetazolamide if IOP raised
Bandage contact lens
Surgical rehabilitation, e.g. amniotic membrane graft, limbal stem cell transplantation

Evidence base

*GRADE: Grading of Recommendations Assessment, Development and Evaluation (see www.gradeworkinggroup.org)
 

Sources of evidence

Bagley DM, Casterton PL, Dressler WE, Edelhauser HF, Kruszewski FH, McCulley JP, Nussenblatt RB, Osborne R, Rothenstein A, Stitzel KA, Thomas K, Ward SL. Proposed new classification scheme for chemical injury to the human eye. Regul Toxicol Pharmacol. 2006;45(2):206-13

Bizrah M, Yusuf A, Ahmad S. An update on chemical eye burns. Eye (Lond). 2019;33(9):1362-1377

Blackburn J, Levitan EB, MacLennan PA, Owsley C, McGwin G Jr. The epidemiology of chemical eye injuries. Curr Eye Res. 2012;37(9):787-93

Eye trauma. 2023 BMJ Best Practice

Chau JP, Lee DT, Lo SH. A systematic review of methods of eye irrigation for adults and children with ocular chemical burns. Worldviews Evid Based Nurs. 2012;9(3):129-38

Dua HS, King AJ, Joseph A. A new classification of ocular surface burns. Br J Ophthalmol. 2001;85(11):1379-83

Haring RS, Sheffield ID, Channa R, Canner JK, Schneider EB. Epidemiologic Trends of Chemical Ocular Burns in the United States. JAMA Ophthalmol. 2016;134(10):1119-1124

Ikeda N, Hayasaka S, Hayasaka Y, Watanabe K. Alkali burns of the eye: effect of immediate copious irrigation with tap water on their severity. Ophthalmologica. 2006;220(4):225-8

Martin GC, Le Roux G, Guindolet D, Boulanger E, Hasle D, Morin E, Vodovar D, Vignal C, Gabison E, Descatha A; French PCC Research Group. Pediatric eye injuries by hydroalcoholic gel in the context of the coronavirus disease 2019 pandemic. JAMA Ophthalmol. 2021;139(3):348-351

Oulee A, Waldrop I, Mendoza R, Onyekonwu C, Plurad DS, Sheets NW. Children ages one to four are disproportionally affected by chemical burns in a cross-sectional analysis of NEISS 2012-2021.Burns. 2023;49(7):1729-1732

Schrage NF, Langefeld S, Zschocke J, Kuckelkorn R, Redbrake C, Reim M. Eye burns: an emergency and continuing problem. Burns. 2000;26(8):689-99

Trauma (chemical)
Version 13
Date of search 10.12.23
Date of revision 29.03.24
Date of publication 11.04.24
Date for review 09.12.25
© College of Optometrists